Earth anchor



Oct. 14, 1930- c R, p R 1,778,372

EARTH ANCHOR Filed April 18, 1928 INVENTOR.

A TTORNE Y.

Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE cnnsrna a. 31mm, or LA oaossn'wrsconsm W EARTH ANCHOR Application filed April 18, 1928. Serial No. 271,048.

My invention pertains to earth anchors of assembling of the earth anchor and which the type which comprises blades hingedly will do away with the necessity of mounting mounted in connection with a shaft and the blades upon bolts, rivets, and the like, as

adapted to be held in unexpanded position bearings.

while the anchor is lowered through a pre- It is still a further object of my inven- 55 pared hole. Afterwards the blades are tion to rovide means whereby the blades caused to expand and enter the earth, giving may be eld in unexpanded position while the anchor such a large bearing surface that the anchor is being inserted in a hole preit cannot thereafter be removed from the pared for that purpose, and means for releasearth. ing the blades as soon as the trunnion hous- 00 My invention is further specifically aping has been hit by the tamping tool, so that plicable to that type of earth anchor in which the further swing of the blades on their trunthere is no screw action or rotary motion nions durin expansion of the anchor will be necessary to expand the blades, but in which free from f ictional resistance.

16 the blades are expanded by the action of a These and other objects to which reference as tamping tool. will be made in the ensuing disclosure 1 ac- Hitherto such anchors have been made complish by that certain combination and with a single pair of cooperating blades. An arrangement of parts of which I have illusexample of such an earth anchor is shown in trated a preferred embodiment.

my Patent N 0. 1,123,368, issued January 5,- In the drawings 1915. Where two cooperating blades are Figure 1 shows a top plan view ofone of provided, the width of the blades is necesmy anchors in expanded position. sarily limited by the width of the original Figure 2 is a sectional elevation of the hole in which the anchor is to be used, and trunnion housing showing two blades mount- 25 the bearing surface of the anchor in the earth ed therein on their trunnions and the anchor is correspondingly limited. The bearing shaft passing through the housing. surface may be somewhat increased by Figure 3 is a perspective view of one of my lengthening the blades, but this also has its blades. limitations, since the blades cannot be Figure 4 is a side elevation of an expanded so lengthened beyond a ceretain point without anchor. so necessitating a redesign of the general struc- Figure 5 is a side elevation of my trunnion ture. houslng showing the opening to accommo- Hitherto, so far as I am aware, there have date the neck of one of my blades and shownever been rovided anchors of this type havin the trunnion bearings in dotted lines. 36 ing more t an two blades. It is an object igure 6 is a view of the unexpanded of m invention to provide such an anchor. anchor as it is prepared to be lowered into It will be clear that several blades, even the hole. 7 though their width be necessarily limited by While I have shown in these views an the permissible over all measurements of the anchor havin four blades, it will be underdevice, will nevertheless have much more stood that I 0 not limit myself to the numbearing surface than an anchor with only two ber of blades in my anchor but may provide blades. more or less, according to the purpose for It is a further object of my invention to which the anchor is to be used, the strain it provide a sim le, inexpensive and efiicient must bear, the character of the soil, etc. The 45 mounting for t e blades which will serve to anchor broadly consists of a shaft 1, a bot- D6 expand all of them at once uniformly under tom plate 2 to the center of which the shaft is im acts of the tampin tool. fastened in any suitable manner, as by means t is still a further 0 ject of my invention of the nut 3 on the threaded end thereof. I to provide a trunnion housing for. mounting have shown also a trunnion housing 4 in the blades which will permit quick and easy which the blades 5 are pivotally mounted. I

This trunnion housing may be of various shapes, and the shape and size of it will vary, of course, with the size of the anchor and the number of blades. I have shown a rounded trunnion housing in which four of the blades are mounted.

Reference to Figure 3 will show that each blade comprises a flat spade-like portion (i, a neck portion 7, and a trunnion portion 8. The axis of the trunnion portion extends at right angles to the neck portion, and beyond it at either side, so that the trunnion may be used as a means of mounting the blade pivotally in the housing. Each blade has a latch or stop portion 9 for a purpose which will be hereinafter described. It is clearly shown, however, in Figure 3 and the other views showing the trunnion in plan or section that the trunnion 8, instead of .being perfectly cylindrical, is made slightly oval or elliptical in cross section so that it is broader "in one transverse direction than in the other.

Reference now to Figure 2 will show my trunnion housing in section. It comprises a body with a top which I have indicated as 10. Below this top there are trunnion sockets 11 in which the trunnions may rotate. The trunnion housing has a bottom portion 12 completin the trunnion sockets but it will be noticed in igure 2 that a portion has been cut away from the trunnion socket bottoms and sides to accommodate the necks of my blades so that these blades may swing through an angle of 90 degrees from the vertical to the horizontal. These portions I shall hereafter refer to as neck openings, and I have indicated them in Figure 5 by the numeral 13. In my trunnion housing there will be a trunnion socket for each of the blades and reference to Figure 1, in which the trunnion sockets are indicated in dotted lines in plan for a fourblade anchor, will indicate somewhat more clearly their general disposition. It will also best be understood from this view that through the center of the trunnion housing is an opening 14 for the shaft 1 and that each of the trunnion sockets are open on the side toward the shaft. It will be understood that this opening is of such a size as to permit the trunnionhousing to slide freely on the shaft 1, and that the width of the trunnion sockets will be such that the trunnions themselves will not bind against the shaft.

It will now be clear why I make my trunnions of elliptical rather than truly cylindrical shape. When the blades are in the vertical position the elliptical trunnions bind in the trunnion sockets since the major axis of the elliptical cross section of the trunnions is made equal to the depth of the trunnion sockets. The trunnion sockets are, however, wider than they are deep. In the sense that the distance between the open end of the socket (which is closed by the shaft 1) and the curved inner end of the trunnion socket is greater than the distance between the top and the bottom of the socket. Thus, as soon as the blades 5 have been started from the vertical position indicated by the solid lines in Figure 2 toward the horizontal position indicated by the dotted lines, the binding of the trunnion against the trunnion socket will. be released and the blade will then swing freely. The purpose of this binding is to hold the blades in the unexpanded position shown in Figure 6 while the anchor is being lowered into a hole prepared for it. As soon, however, as the tamping tool has been applied to the body of the housing and the blades started from their vertical position, the frictional binding of the trunnions and the sockets, as has been said will be released, and the blades will expand freely into the earth under the. im acts of the tamping tool.

The latch or stop 9 is designed to pass over the edge of the bottom or stop plate 2 of the anchor after tne expansion of the blades into the earth and to stop the blades thereagainst from subsequent retraction when strain is aplied to the shaft of the earth anchor. Stop means are of course necessary in the operation of directly expanded earth anchors of this type, and I do not claim any particular novelty in this stop means.

In assembling my earth anchor I take my trunnion housing 4. and a set of blades to correspond, and I mount the blades upon their trunnions in the trunnion sockets by passing the blade trunnions up through the hole 14 for the shaft and then sidewise into the trunnion sockets. Then I insert the shaft 1 in the hole 14, whereupon the shaft forms a closure for the open sides 01 the trunnion sockets and the 'blades will now be loosely but permanently mounted in the housing. I then slip the bottom plate 2 over the threaded lower end of my shaft, attach the nut 3, and the anchor is complete. The blades are collapsed against the shaft as far as they will go, whereupon, as explained, the elliptical trunnions bind in the sockets and the blades are temporarily held against expansion sothat-the entire anchor may be conveniently inserted into a hole in the earth. The manner of use of the anchor is well known and need not be described by me.

Various modifications in my device will be within the province of those skilled in the art in adapting it to various conditions. I have already indicated that the number and disposition of the blades may be varied. The blades may be mounted otherwise than upon integrally formed trunnions. A binding pressure so as to hold the blades in collapsed position mav be otherwise applied than by means of the elliptical trunnions. For example, the friction may be applied at the ends of the cylindrical trunnions and may be constant thoughout the limits of the movements of the blades so that the ex ansion of the earth anchor may be effected by the tamping tool against frictional resistance all of the way.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In an earth anchor a shaft and a bottom plate thereon, a trunnion housing slidably mounted on said shaft, trunnion sockets in said trunnion housing, a plurality of blades each having a trunnion, and said trunnions mounted in said trunnion sockets and held therein by said shaft.

2. In an earth anchor a shaft and a bottom plate thereon, a trunnion housing slidably mounted on said shaft, trunnion sockets in said trunnion housing, a plurality of blades each having a trunnion, said trunnions mounted in said trunnion sockets and held therein by said shaft, and means for holding said trunnions against rotation in sa1d sockets, said means comprising a frictional engagement of said trunnions in said sockets.

3. In an earth anchor a shaft and a bottom plate thereon, a trunnion housing slidably mounted on said shaft, trunnion sockets in said trunnion housing, a plurality of blades each having a trunnion, said trunnions mounted in said trunnion sockets and held therein by said shaft, and means for releasably holding said trunnions against rotation in said sockets, said means comprising a frictional engagement in one position between said trunnions and said sockets, said sockets being wider than they are deep, and said trunnions being of elliptical form.

4.. In an earth anchor a trunnion housing comprising a central hole for a shaft, interior trunnion sockets opening to said shaft hole and arranged thereabout, whereby trunnions may be inserted therein, a plurality of blades each having an earth engaging portion, a neck and a trunnion, neck openings in said trunnion housing conecting with said sockets to accommodate said necks during a swinging of said blades, said trunnions being mounted in said trunnion sockets and held therein by a shaft passing through said hole.

5. In an earth anchor a trunnion housing comprising a central hole for a shaft, interior trunnion sockets opening to said shaft hole and arranged thereabout, whereby trunnions may be inserted therein through said shaft hole, a plurality of blades each having an earth engaging portion, a neck and a trunnion, openings in said trunnion housing connecting with said sockets to accommodate said necks during a swinging of said blades, said trunnions being mounted in said trunnion sockets and held therein by a shaft passing through said hole, and frictional means for binding said trunnions in said trunnion sockets.

6. In an earth anchor a trunnion housing comprising a central hole for a shaft, inte- I'lOI trunnion sockets opening to said shaft hole and arranged thereabout, whereby trunnions may be inserted therein, a plurality of blades each having an earth engaging portion, a-neck and a trunnion, openings in said trunnion housing connecting with said sockets to accommodate said necks during a swing ing of said blades, said trunnions bein mounted in said trunnion sockets and held therein by a shaft passing through said hole, said trunnions being elliptical in cross section, the longer aixs of said elliptical cross section coinciding with the major axis of said blades and being of such length as to cause said trunnions to bind in said sockets when said blades extend at right angles to said housing, said trunnion sockets being shaped to release said trunnions when said blades have been substantially moved out of said right angular position.

7. In an earth anchor a shaft and a bottom plate, a housing slidably mounted on said shaft, trunnion sockets in said housing communicating with a hole to accommodate said shaft, a plurality of blades each having a trunnion, said trunnions mounted in said trunnion sockets and held therein by means of said shaft, whereby when a tamping tool is applied to said trunnion said blades may be caused to swing outwardly from a substantially vertical to a substantially horizontal position, thereby entering the earth, and means on said blades to stop said blades against said bottom plate from retraction.

8. In an earth anchor a shaft and a bottom plate, a housing slidably mounted on said shaft, trunnion sockets in said housing communicating with a hole to accommodate said shaft, a plurality of blades each having a trunnion, said trunnions mounted in said trunnion sockets and held therein by means of said shaft, whereby when a tamping tool is applied to said trunnion said blades may be caused to swing outwardly from a substantially vertical to a substantially horizontal position, thereby entering the earth, and means on said blades to stop said blades against said bottom plate from retraction, and means for releasably holding said blades in vertical or unexpanded position.

CHESTER R. PIEPER. 

